HARBOUR EXTENSION SCHEME.

Taranaki Daily News, Volume XXIII, Issue 271, 16 November 1901, Page 2

HARBOUR EXTENSION SCHEME.

MR. rUPIER BELL'S HKPORT. The following is Mr. Napiar Bell's report totha Haroour Board on the sub- , ject of increased accommodation for shipping and the extension df shoher no essay to i-e provided for the same : I wi'l fir.-fc 'ak* in'o consideration >, tho often propose! project of nuking a j bivakwater from Miko'ahi Po nt to

Moturoa Island arid from that island starting a bretkwater to enckss a deep' • wa'er Mr. James Balfo'ir in ' 1866 an-1 Mr. John Canuthers in 1879 i reported on this subject, and no new ligh ; that; I know of has been thrown on it. To rn vke such a harbour it would ba necessiry to make a breakwatar of tbe strongest description from Mikotahi Point to Mosuroa Island, as a very heavy sea drives through this str->it; the distanoa is 1130 fe9t and the c st would be about £60,000. Tom the real shelter for such a port would be efi'ejtad by a breakwater ia an easterly direction from Moturoa Island, but' tnis must bo built in depths of 42 feet of watti' at Ijw water. To build this breakwater of rubble would cost about £9B per running foot, but I doubt whether sufficient stone of suitable size is to bj hid in this neighbourhood. If the is n <t of saitab'e size then it must be built of concrete blocks on a rubble mound, the top of which would be 15 fe*t or S3 under low watsr with wave breakers of rubble blocks on the! outside, and this structure would cost: about £125 pT running foot. But] apart from the cist o? the breakwater, the si' e has many iticonvenieoces; the bottom whare the wharves wou?d be is said to be all roclr, and to g t at these fffc.Hrv.-8 the r il«;iy would have to cross over on the breakwater between Mik-itahi and Motuoi Isknd, tbe objection to which is that in a heavy sea the spray would fly wildly ovor the traiD. The only advantege this position bus over *lw pre ent fi'e is that no , dredging woul 1 have to bH dune to admit thf< very largest vfsspl to the • wharve-, but if dredging is d ne on tha \ present site then it is better and more convenient than the site of Moturoa Island, and I hive no doubt that the cheaper cost of a breakwater on the pre-ent site vfbuld more than pay for the , dredging rtquiied to admit the largest 1 vessels. In any case the time has passed when the Moturoi site c uld be seriously considered. At present the I consideration is to extend the existing f breakwater to something like tbe length originally designed by Mr J. 3 Oarruthers, which would have given a 1 splendid harbour with abundance of 3 water. But the fact of the drifting of J sand round the breakwater must modi- > fy one's ideas as to the capacity of the harbour, because, although the breakf waters might be made to enclose any 1 quantity ofde'jp water, yet the sand in ■ time will fill all up which is not kept I deep by dredging. In this respect the j M.oturo-1 site would not offer any ad- » vantage, because, if the breakwaters had been made there originally, I have j little doubt that by this time the sind j would have found its way round th" s end and into the harbour, and there- '<• fore dredging would have had to i.e ! done even at the, Moturoa site. The l question of sites for this port has been i| carefully considered by Sir John Coode, - Mr John Oarruthers, and Mr Bhckett, '" and after studying the chirt of sound- '" ings made by Mr Edgar O. Jones, one can see that the site of the present I breakwater is, mt ill-chosen. It is true ~ that the water is somewhat shallow t close inshore, but the offing all round e and well into the l<nd towards the '• east is very defp; consequently th< I approach is safe and easy to navigate s both out and in. It is very creditable ■- to the harbour officers that they havf d managed so well with the breakwater '" short ts it is, so that in the year onlj i- four vessels have had to piss bj d through stress of weather. But ru J one doubts that the breakwater is fai '' too short for efficient shslter, and con sequently considerable damage ia in currei to ships, to the wharf, and tc the tackle used, not to mention th< r t risk of being caught in such a nirro« 1 pi tee in a gale- of wind. All sucl a disadvantages would be quite abatee '; if the breakwater were lengthened

in which c\ne vessels berthed in this port wou'd fear mo weacher. After carefully considering Mr Marhant's project for extension of tbe breakwater, I come to the conclusion that the «x l ent to which he proposes to lengthen it is about as much as is admissible in view of the dredging that will be required, and to my mind

enough for the trade of the district now or in the future. I have agreed with him that it is not admissible at present tw make the past wall as shown in his plaD, although it can be undertaken

in the future when, as he shows, it would afford good sites for additional shipping berthage. At present it would serve a better purpose if some of the cost of it were taken to still further lengthen the breakwater, which would therefore be extended 1060 feet. This would give a very good shelter to the present wharf when also extended, and

also to an additional wharf, which is shown on the plan, to be erected in the future when required and referred to at the end of this report. I would re-i commend the breakwater to be built of rubble stone capped with concrete blocks, that is, provided that sufficient rock is to be had. It seems doubtful if there is sufficient rods in the present quarries, and if cot then the Paritutu Hill must be quarried. The original intention of Sir J. Coode and Mr C*rruthers was to use this hill ss a qu.irry. Those who have examined the stone do net think much of its appearanc ', but it should bs prospected t> see if good eouud stone is to be had. When the breakwater is lengthened, the present wharf is to bo extended 400 feet by a width of 50 feat, which permits of the berthage of two of the largest steamers, aud le&ves tbe existing wharf for the use of smaller vessels. The dredging as defined by Mr Mnr- ! chant is quite suitable, and the only question is as to tbe cost of it, as from j want of borings one cannot t ; 11 how much is sand and how much soft sindj stone. It shows a large area under | shelter of the breakwater to be dredged [to 25 feet below low water with one [ berth on the inside of the wharf extents ton" dredged to 30 feet. I quite agree that it is good policy to dredge inshore instead of extending the breakwater so ■is to avoid dredging, as it is in this jase far cheaper to dredge than to ex-

tend thu works into deeper wa'er. Much of this nraa shown to ba dredged is liable to be imra or less siltoJ up by drift stud coming round the end of the breakwater; but when once tbo dredging is down to the depths shown, the quantity coming round is not increased thereby, and the depth of the port will then be maintained by the yearly amount of dredging required to keep down the drift, whatever the amount may be, I agree with Mr Marchant that to dredge cheaply and 1 wit)» dispatch the port should possoaa a

good Hand pump dredge with a hopper 1 capacity of about 250 tons. Mr Marcbant thinks it muse be mounted with ' a bucket ladder to dredge hard m»t«- ' rial, and if there is much hard material ' no doubt that is necessary, but I think ( 1 borings should be taken over the area to bs dredged bafore purchasing a i dredge. When once the entire dredg- ' liug is done to the depths proposed, [then nothing but tho sand pump will J be uoudel to main ain the depth, and this can b i done nt a v»i y uud >nue yoar'y co<t if the quantity is no mire than 70,000 cubic yards a ye*r. In. making designs for extension of the] shipping accommodation, it hag occurred to me that it were as well to see what provision coull be made for the utmost accommodation which the proposed extension of the breakwater would admit of, even although it is not contemplated at present. With this view I have indicated on plan herewith an additional whirf for large steamers with a wharf inside of it for smaller (vessel?, this latter being protected by a ! rubble bank which forms the approach jto the deep water wharf. The lines of rail giving access to these wharves would be placed on reclaimed land as shown on plan. The breakwater extension proposed would therefore give shelter to wharves with a to v al berthage length of 3170 feet, that is, for about nine vessels, four of which would be of the largest eiz°, and New Plymonth would ba very prosperous indeed if it could find trade for all this shipi ping. The following is an approximate i estimate of the proposed works, not including the additional wharves and reclaimed land mentioned in the last paragraph : Breakwater extension 1060 feet at £75 -£79,875. Inclined approach in concrete, £ISOO. Wharf extension, £IO,BOO. Dredging, say £17,000. New dredge, £16,000. Moorings, £ISOO. Extra plant, £3500 -£130,175. Contingencies, 10 per cent., £13,017. Total, £143,192.